Papers of the Week

Cationic starch microparticles (CStMPs) loaded with 4-amino-3 -(phenylselenyl)benzenesulfonamide (4-APSB) were prepared and investigated in a model of fibromyalgia (FM) induced by intermittent cold stress (ICS) in male and female Swiss mice. The CStMPs/4-APSB were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, zeta potential, and particle size measurements, providing information about their chemical composition, surface charge, morphology/microstructure, and size (1.50 ± 0.5 μm). Following ICS exposure, the animals were treated with free 4-APSB (1 mg/kg), CStMPs/4-APSB (containing 0.13 mg of 4-APSB per mg of microparticles), or CStMPs, from days 5 to 10. The results revealed the successful incorporation of 4-APBS in the CStMPs. Free 4-APSB and CStMPs/4-APSB reversed nociceptive- and depressive-related behaviors in male and female mice exposed to ICS, attenuating the hallmark symptoms of FM. Those treatments (free 4-APSB and CStMPs/4-APSB) normalized the monoamine oxidase (MAO)-A activity in the cerebral cortex and the oxidative damage, providing the correct functioning of the enzyme Ca -ATPase in the cerebral cortex and hippocampus of mice exposed to ICS. The CStMPs/4-APSB modulated the oxidative stress markers, specifically in the spinal cord of mice – an anatomical region intricately linked to pain pathways.